Skip to content
OpenAdvisories
Medium · 6.5 CVE-2026-107294 EUVD-2026-95104GHSA-v2xh-2vp8-57h8PYSEC-2026-4280PYSEC-2026-4289

Pydantic AI: Unbounded memory use when downloading remote content via web_fetch or FileUrl

Published Oct 8, 2026 · Updated Oct 9, 2026 · Assigned by GitHub_M

Description

Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.2 and 2.24.0, web_fetch_tool, the WebFetch local fallback, and remote FileUrl media downloads buffer the complete HTTP response body before enforcing content-size controls. An attacker-influenced URL can stream an arbitrarily large response that exhausts process memory and crashes the worker; affected media types include ImageUrl, DocumentUrl, VideoUrl, and AudioUrl. SSRF protections remain effective, and the impact is limited to availability. This issue is fixed in versions 1.107.2 and 2.24.0.

Affected products

VendorProductAffectedFixed
pydantic pydantic-ai >= 1.77.0, < 1.107.2, >= 2.0.0b1, < 2.24.0 —
pydantic pydantic-ai-slim >= 1.77.0, < 1.107.2, >= 2.0.0b1, < 2.24.0 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI pydantic-ai >= 1.77.0, < 1.107.2 1.107.2 GHSA-v2xh-2vp8-57h8
PyPI pydantic-ai >= 2.0.0b1, < 2.24.0 2.24.0 GHSA-v2xh-2vp8-57h8
PyPI pydantic-ai >= 1.77.0, < 1.107.2 · >= 2.0.0b1, < 2.24.0 1.107.2, 2.24.0 PYSEC-2026-4280
PyPI pydantic-ai-slim >= 1.77.0, < 1.107.2 1.107.2 GHSA-v2xh-2vp8-57h8
PyPI pydantic-ai-slim >= 2.0.0b1, < 2.24.0 2.24.0 GHSA-v2xh-2vp8-57h8
PyPI pydantic-ai-slim >= 1.77.0, < 1.107.2 · >= 2.0.0b1, < 2.24.0 1.107.2, 2.24.0 PYSEC-2026-4289

References